Using functions defined in primitive modules

Question

I\'d like to make use of this function:

u8::from_str(src: &str) -> Result

I can\'t seem to figure out the syntax to use it. Thi

Answer 1

The trick here is that from_str is actually part of the trait FromStr. You need to use that trait, then specify which implementation you want to use:

use std::str::FromStr;

fn main() {
    match ::from_str("89") {
        // Stuff...
    }
}

However, this particular concept has a more ergonomic option: parse:

fn main() {
    match "89".parse::() {
        // Stuff...
    }
}

And you might be able to remove the :: if something else constrains the type enough for it to be inferred.